Remember the Sony HMZ-T2 3D head-mounted display that we tried on back at IFA? Well, it's being prominently featured here at TGS, too. Tucked away at a smaller, much more modest booth around the corner, however, is something a smidge more interesting. Kept behind glass and a safe distance away from our grubby mitts and sweaty foreheads resides the "Prototype-SR" (Substitutional Reality) that was outted on YouTube last week. Essentially, the unit appears to be the HMZ-T2 with a front-mounted camera for head tracking and camera functionality -- the...